Photochemistry of Spiropyrans in a Porous Glass Impregnated with Polymethyl Methacrylate

摘要

It is found that a system consisting of spiropyrans in a porous glass impregnated with polymethyl methacrylate is characterized by both reversible photobleaching under irradiation with visible light (typical of spiropyran adsorbates in porous glass) and reversible photocoloration (which is not observed for adsorbates). Regularities of changes observed in absorption spectra on irradiation and subsequent dark relaxation are analyzed, and the conclusion is made that in porous glass impregnated with polymethyl methacrylate, spiropyran adsorbates on porous glass and its solutions in the polymethyl methacrylate phase coexist.